Naphthylpyrazolone sulfonic acid.



UNITED STATES PATENT OFFICE. PAUL VOLKMYANN, or ELBERFELD, GERMANY, 'ASSIGNOR 'ro FARBENFABRIKEN vonMi FRIEDR. BnYER & 00., or ELBERFELD, GERMANY, A CORPORATION OF GERMANY.

NAPHTHYLPYRAZOLONE SULFONIC ACID.

tor of philosophy, chemist, citizen of the- German Empire, residing at Elberfeld, Gercooling are filtered oil and dried.

many, Kingdom of Prussia, have invented new and useful Improvements 1n Naphthylpyrazolone Sulfonic Acids, of which the following is a specification.

My invention relates to the production of the hitherto unknown naphthylpyrazolone sul 'onic acids having the following general formula co i -oh,

on, (X meaning the radical of naphthylamin sulfonic acids).

The process consists in condensing the naphthyl hydrazin sulfonio acids (obtainable by reducing the diazonaphthalin sulfonie acids) with aceto acetic ester. The new pyrazolone derivatives thus obtained are valuable intermediate compounds for the production of new azo dyestufl's which are obtained by combining diazo com ounds with these products. 'lhey are grayis 1 compounds soluble in hot water and form easily soluble, well crystallizing sodium salts. 'lhe dilute acid solutions of the new compounds yield on treatment with nitrous acid yellow nitroso compounds.

In order to carry out my new process I can e. 9. proceed as follows, the parts being by weight: A solution of 48 parts of crystallized sodium acetate in 192 parts of water is added to a paste obtained by mixing 100 parts of 2 naphthylhydrazin 4.8 disulfonie acid with 650 parts of water heated to 70 C. The stirring of the mixture which has" to show a slightly acid reaction on congo paper is continued while 42 parts of aceto acetic ester are added to it. Itis then heated to 80 C. and salt is added. 'Ihe pyrazolone crystallizes in colorless needles which after 'I he reaction which occurs is explained by the followv Specification of Letters Patent.

Application filed June 17, 1908.

ble in hot water.

Patented. Jan. 19, 1909.

Serial No. 439,073. (Specimena) The 1 beta naphthyl 4.8 disulfonic acid 3 methyl 5 pyrazolone is in the shape of the free acid a grayish powder solu- -'Ihe dilute acid solution yields on treatment with nitrous acid a yellow nitroso compound.

'I he process is carried out in an analogous manner on preparing pyrazolones from other hydrazine of naphthylamin -sulfonic acids e. g. of 1.4, 1.5, 1.6, 2.5, 2.6, or 2.8-naphthylamin sulfonic acids or of 2.3.6, 2.5.7, 2.6.8 naphthylamin disulfonic acids, 1- naphthylamin-3.5.7-trisulfonic acid etc.

Having now described my invention and in what manner the same'is to be performed, what I claim as new and desire tosecure by Letters Patent is z a 1. The herein-described new naphthylpyrazolone sulfonic acids having the formula:

d N/ \CO d-cii t X meaning the radical of naphthylamin sulfoni c acids which compounds are grayish powders soluble in hot water, forming easily solublc, well crystallizing sodium salts; and yielding yellow nitroso compounds on treatment of their dilute acid solutions with nitrous acid,

' substantially as described.

2. 'lhe herein described new 1 betanaphthyl 4.8 disulfonic acid 3 methyl- 5-pyrazolone of the formula:

PAUL VOLKMANN. [L. s.]

Witnesses:

Or'ro KoNIG, WM. WAsmNcroN Bounswrcx.

Correction in Letters Patent No. 910,437.

It is hereby certified the. in Letters Patent No 910,437, granted January 9, 1909,

upon the application of Zaul Volhnuann, of Elberfield, Germany, f0r an improvement in Naiphthylpyrazoione Sulfimic Acids, an errorappears in the printed specification requiring correction, as follows: In line 75-80, page 1, the formula:

it it B should read B e'--0H, 00H

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 16th day of March, A. 11,1909. [SEAL] o. 0. BILLINGS,

Acting Commissioner of Patents.. 

